Researchers from Trinity College in Dublin have made a breakthrough in treatment for age-related macular degeneration (AMD) – the leading cause of blindness in people over 50.

Through their research, they have discovered that interleukin-18 (IL-18), a component of the immune system, can protect patients from vision loss, and it can be administered in a non-invasive way, Fox News reports.

AMD has two major forms: “dry,” the more common form, and “wet,” which accounts for 90 percent of the severe vision loss caused by macular degeneration.  When a patient suffers from wet AMD, the blood vessels grow into the retina,  and begin to leak blood or fluid – causing immediate retinal blindness. 

In order to combat wet AMD, patients must undergo eye injections of antibodies that inhibit a molecule called VEGF – which is responsible for stimulating the overgrowth of blood vessels into the retina.  These injections are effective, but they can be extremely uncomfortable, and patients must receive them on a monthly basis.

Researchers say IL-18 can work just as effectively as these anti-VEGF injections.

To test their findings, study author Matthew Campbell, research assistant professor in genetics at Trinity Campbell and Sarah Doyle, an assistant professor in immunology at Trinity and first author of the study, analyzed IL-18’s effects in mice. They mimicked the damage that wet AMD patients experience by using a very fine laser to damage the backs of the mice’s eyes. They then administered a form of IL-18 that GlaxoSmithKline had been developing as a potential cancer therapy.

This drug screening showed that IL-18 was able to prevent the leakiness of the blood vessels into the retina, as well as stop their overgrowth. Since IL-18 is pro-inflammatory, the researchers were concerned about patient tolerance, but preliminary human trials have shown that low doses have no adverse side effects, other than a very low-grade fever.