Researchers at the University of Virginia in the US have discovered a critical trigger for macular degeneration, the leading cause of vision loss among the elderly. The finding may allow doctors to halt the inflammation early on, potentially saving millions of patients from blindness.

Researchers say they have found one of the very early events that trigger the inflammation, which ultimately damages cells in the retina and causes blindness. By being able to interfere in the very early stage of the onset of macular degeneration, doctors would be able to provide effective treatment for the disease.

The new research has identified an enzyme called cGAS as being responsible for triggering the onset of macular degeneration. The same enzyme also plays an important role in the body’s immune system against infections.

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. Because the target is an enzyme, researchers say they could develop small molecules that could block it. There are many drugs already on the market that target specific enzymes, such as the statins, which are used to lower cholesterol levels, the team pointed out.

The promising new lead comes as good news for researchers seeking to develop new treatments for dry macular degeneration, as clinical trials in recent years have come to dead end after dead end. Over 200 million people around the world are estimated to have macular degeneration.

The UVA researchers expect the development of a drug to inhibit cGAS will take several years, and that drug would then need to go through extensive testing to determine its safety and effectiveness for combating macular degeneration. The researchers also hope to develop a way to detect the levels of the enzyme in patients' eyes, which would let them determine when best to administer a treatment that blocks cGAS.