New Light on Blindness-Causing Disease
Cleveland Clinic researchers' breakthrough technique helps analysis of drusen, which leads to age-related macular degeneration.

A technique developed at the Cleveland Clinic Cole Eye Institute and related protein analysis could provide the key that unlocks the mystery of age-related macular degeneration, a disease that affects millions and has no known cause or cure.

The Cleveland Clinic research was presented at the annual meeting of the Association for Research in Vision and Ophthalmology. The strategy combines a new technique that isolates drusen, the precursor of AMD, with mass spectrometric protemic analysis. Joe G. Hollyfield, Ph.D, and John W. Crabb, Ph.D., are leading the ongoing research. The Cleveland Clinic is the only site in the world using the new Drusen Isolation Method for Proteomic Analysis.

The researchers are part of a team recruited by Hilel Lewis, M.D., chairman of The Cleveland Clinic Cole Eye Institute, to study ways to cure age-related macular degeneration.

"Age-related macular degeneration is a common disease with links to both genetic and environmental causes. We just don't know enough to understand it," Dr. Lewis said. "I believe that this technology and line of research will bring us closer to the cause of age-related macular degeneration."

The National Institutes of Health, Merck Inc., the Foundation Fighting Blindness and The Cleveland Clinic funded research for both programs.

Approximately 12 million people are affected by age-related macular degeneration, which damages central vision and is the leading cause of blindness in individuals age 55 and older. Ophthalmologists long have known there is a relationship between AMD and drusen, which are abnormal deposits that collect on the Bruch's membrane behind the retina. But until now, there hasn't been an effective procedure to obtain drusen for analysis so researchers can probe the molecular link between AMD and drusen.

"We developed a technique that allows us to obtain drusen from donor eye tissues by taking drusen off the membrane at the back of the eye," said Dr. Hollyfield, director of research at The Cleveland Clinic Cole Eye Institute. The research was based on 55 donor eyes, some normal and some with AMD, which were provided by the National Disease Research Interchange and the Foundation Fighting Blindness.

Scanning the Bruch's membrane at 20-to 40-diameter magnification, Dr. Hollyfield evaluated the membrane surface for drusen and then used a delicate watchmaker's forceps to dislodge the drusen. A single eye can provide up to 10 ug of protein for subsequent biochemical analysis.

The availability of isolated drusen created a virtual explosion of proteomic information, Dr. Crabb said.

"Before now, we knew of only approximately 20 proteins present in drusen. We have now identified more than 120 proteins from drusen and Bruch's membrane by protein mass spectrometric methods, and we're just getting started," said Dr. Crabb. He said the new strategy means he and other researchers can more effectively study the molecular mechanisms involved in drusen formation.

"This is the future. The next breakthrough in understanding AMD will come by protemic research," said Dr. Crabb. "Our preliminary results from the analysis of 23 different drusen preparations suggest that the proteins contain oxidative modifications that contribute to both drusen formation and Bruch's membrane thickening."

The Cleveland Clinic Cole Eye Institute is ranked one of the top eye care departments in the country, according to a recent survey published by U.S. News & World Report. More than 125,000 patients were treated at the Institute in 2001. The Institute has state-of-the-art eye clinics, operating rooms for eye surgery, and more than 20,000 square feet of laboratory and clinical space dedicated to research on age-related macular degeneration and inherited retinal disease.

Here is a link that might be useful: New Light on Blindness-Causing Disease

Hi pawprint... Thanks for the info. They have a wealth of info based there and very well done. My sister is being tested at Cleveland Clinic to see if she's eligible for experimental surgery in treating MD. If conditions are OK, she will be part of a study being conducted free of charge. Of course, there has to be a control group, so 1 out of 3 patients will be injected with a placebo (sp???). Seems like a high number of placebos... There are risks involved. That's why I was hoping to find someone with some experience with the process. ~abreeze

Wow, I hope she gets the study that works! I'm not familiar with the process but am very familiar with Cleveland Clinic. Used to work there. Excellent facility. Good luck for you and your sister!

They did the surgery...