OHSU Researchers First to Use New Technology To Spot Rare Eye Infection

03/21/00    Portland, Ore.

Scientists at Casey Eye Institute Utilize Confocal Microscope to Discover Method that May Make Diagnosis Easier

It's an infection that sometimes surfaces in contact lens wearers. Acanthamoeba infections may be rare, but if they go untreated, they can be painful and lead to vision loss. Now, thanks to the latest technology, ophthalmologists in the Casey Eye Institute at Oregon Health Sciences University are able to spot the problem, often before a patient knows something is wrong.

Acanthamoeba is a microscopic organism that lives freely in soil and fresh water. From time to time it surfaces in the eye, usually through contact lens insertion. This can lead to infection. In the early stages, a common symptom is dry eyes. Later on, acanthamoeba can cause a ring-shaped mark on the cornea. Diagnosing these infections has always been difficult. Ophthalmologists could identify the problem, but they were not always able to determine its cause.

Thanks to a piece of equipment known as a confocal microscope, diagnosing acanthamoeba infections may now become much easier. William Mathers, M.D., professor of ophthalmology, School of Medicine, in the Casey Eye Institute at OHSU, was the first to locate the organism in the eye using the confocal microscope. DNA testing confirmed this discovery. So far, Mathers has been able to identify at least 25 patients with the early stages of acanthamoeba infections. All received the appropriate treatment before the situation became serious. The results of the study are published in the February issue of the journal Archives of Ophthalmology.

"For years, diagnosing acanthamoeba has posed a problem for physicians," said Mathers. "The organism had been identified in a laboratory setting, but never in the human eye. This is just one of the many areas where the confocal microscope can benefit our patients."

The microscope can be used to study the surface of the eye and the cornea up close. Unlike traditional microscopes, the confocal microscope does not require the study material to be mounted on a glass slide. The microscope was purchased through the Oregon State Elks Association. In the last 50 years, the Oregon Elks have donated close to $7 million to OHSU. The organization also funds the Elks Children's Eye Clinic. Their dollars pay for personnel, the latest equipment and technology, medical supplies, as well as corrective eyeglasses and contact lenses for those who could not otherwise afford them.

As for OHSU researchers, the next step is to learn more about acathamoeba. The Casey Eye Institute researchers are currently growing the organism in a laboratory setting to allow for further study. "We still have a lot to learn about this organism," said Mathers. "Through the use of this new technology, we have a chance to find out much more."

The National Eye Institute, a component of the National Institutes of Health, and the Iowa Lions club funded the study. The research was conducted in cooperation with the University of Iowa.