In a major step forward in the battle against macular degeneration, the leading cause of vision loss among the elderly, researchers have discovered a critical trigger for the damaging inflammation that ultimately robs millions of their sight.
The finding may allow doctors to halt the inflammation early on, potentially saving patients from vision loss.
Ambati and Nagaraj Kerur, PhD, assistant professor in the Department of Ophthalmology at the University of Virginia School of Medicine, and their laboratories have determined that the culprit is an enzyme called cGAS.
The enzyme plays an important role in the body’s immune response to infections by detecting foreign DNA.
But the molecule’s newly identified role in the “dry” form of age-related macular degeneration comes as wholly unexpected.
“Almost 200 million people in the world have macular degeneration. If macular degeneration were a country, it would be the eighth most populated nation in the world. That’s how large a problem this is,” said Jayakrishna Ambati from University of Virginia School of Medicine in the US.
The researchers noted that cGAS may be an alarm not just for pathogens but for other harmful problems that warrant responses from the immune system.
The researchers also hope to develop a way to detect the levels of the enzyme in patients’ eyes. That would let them determine when best to administer a treatment that blocks cGAS.
The enzyme may also play important roles in conditions such as diabetes, lupus and obesity, and researchers already are working to create drugs that could inhibit its function.