Queen’s look into vision loss illness

The leading cause of vision loss in the elderly occurs when the central region of the retina, the macula deteriorates. This is known as age-related macular degeneration or AMD

Now, Queen’s Professor Anne Hughes and her team in Medical Genetics and Vision Sciences at the Royal Victoria Hospital have reported the risk of AMD in old age can be predicted from a combination of genes and smoking levels.

Professor Hughes said: “The macula is the tissue at the back of the eye that converts light into electrical messages and sends them into the brain. AMD destroys the central vision that is needed for reading and driving, leaving only dim, blurred images or a black hole at the centre of vision.

“In our study of 401 AMD patients and 266 people with good vision, we found it is possible to predict an individual’s risk of developing AMD. We asked each person about their smoking status and catalogued inherited sequence variations within their DNA. We also examined groups of genetic variants known as haplotypes which are present on chromosomes.

“Our research confirmed the two most important gene regions that affect AMD risk. Until we learn more about how these genes act, it will be difficult to prevent the degeneration of the macula. What is clear in the meantime though, is that those at high genetic risk of AMD should try to control their smoking.”

Professor Hughes added: “Our plans for the future include identifying additional AMD genes and explaining the pathways that are important for maintaining healthy eyes. Then it may become possible to prevent AMD or delay its onset.

“The results of this research provide physicians with a way to identify those at the highest genetic risk of developing AMD. They can then step up their efforts to persuade these people to avoid smoking, thereby more than halving their risk of becoming blind.

“In the future, when effective long term treatments for AMD become available, the risk scoring system could also help doctors decide which of their elderly patients should be monitored most intensively for the early signs of AMD. They can then be treated before their vision is irreversibly damaged.”