breakthrough in medical research is poised to help physicians determine well in advance whether a patient will suffer from age-related macular degeneration, the leading cause of vision loss among people age 50 and older.

The key is microRNAs, small molecules that are produced in cells and secreted in body fluids. They regulate gene activity. Detecting a specific microRNA signature can predict if someone will develop a particular disease, so microRNA diagnostic tests are the leading edge of advanced screening for various cancers.

Dr. Mike Sapieha of the Centre de recherche Hôpital Maisonneuve-Rosemont, a research centre affiliated with the Maisonneuve-Rosemont Hospital in Montreal, and Dr. Vincent De Guire, a clinical biochemist at the hospital, launched a study to determine if microRNAs could be used to help with advanced diagnosis of wet AMD.

To investigate, they enlisted graduate student Catherine Ménard and collaborated with Dr. Flavio Rezende, a retinal specialist at the hospital, who began collecting fluid samples from patients being treated for wet AMD.

The team studied the microRNAs that were present in these samples, and the results were very promising. They discovered a wet AMD disease signature involving three different microRNAs. They also discovered this same signature could be detected in blood samples.

Using this microRNA signature, they were able to determine who had the wet form of AMD with 90 percent certainty.

The team is now preparing to move to the next research step, which will involve a much larger, longer-term study of AMD patients. This clinical study will allow the team to answer two very important questions:

1) Will the microRNA signature change over time?

2) Can the microRNA signature predict who will develop wet AMD?

Ultimately, the results of these tests could change how physicians care for people living with AMD by enabling both predictive testing and early treatment.