Scientists at Trinity College have made a discovery that may lead to new ways of treating one of the most common diseases of the eye.

The breakthrough is predicted to lead to new therapies for treating dry age-related macular degeneration (AMD), which can cause total blindness in sufferers, and for which there are currently no approved therapies.

The scientists discovered a component of the cells lining the retinal blood vessels - known as claudin-5 - may be central to the development of AMD. Pre-clinical models have established that “leaky blood vessels” pre-dispose the eye to developing features of the disease.

The finding could have “major implications” for preventing the disease, according to the study, published in the JCI Insight journal.

“We were initially surprised that these blood vessels of the inner retina contributed to an AMD-like pathology, however it now appears that their dysfunction may represent one of the earliest initiating factors of the disease,” says Dr Natalie Hudson, researcher at Trinity, and first author of the study.

AMD is the most common form of central retinal blindness in the aging population. The disease makes everyday tasks such as reading, watching TV, driving, or using computers more difficult and in some cases impossible.

There are two forms of AMD, “dry” and “wet”. While therapies are available for the management of wet AMD, there are no treatments, therapies or cures yet approved for dry AMD, which accounts for the majority of cases in Ireland and worldwide.

Patients living with dry AMD are told to pursue lifestyle changes, such as stopping smoking, and improving diet and exercise regimes. The scientists say new forms of therapy are desperately needed in an ever-aging society, with life expectancy currently far exceeding the rate of development of drugs for aging associated conditions.

“Identifying the early molecular events that cause dry AMD will allow us to develop a targeted approach to therapy,” says Dr Matthew Campbell, assistant professor in genetics at Trinity. “In this case, we believe that regulating the integrity of the retina’s blood vessels may, over time, help to prevent the development of dry AMD.”

The research, which was published this week, was supported by Enterprise Ireland, Science Foundation Ireland and The Royal Victoria Eye and Ear Hospital Research Foundation.