Age-related Macular Degeneration (AMD) is the leading cause of sight loss in people aged over 50 in Ireland.
The condition affects the macula, a small part of the retina responsible for central vision and seeing detail. AMD starts in one eye and often goes on to affect the other eye at a later stage.
There are two types of AMD which is often confusing for people. The first type, variously known as dry or atrophic AMD, develops slowly, leading to [central vision] blindness. It is currently untreatable.
The second type, known as wet or neo-vascular AMD, develops more rapidly but is treatable. However, either form can subsequently develop after the initial form has been diagnosed and/or treated.
"Both forms start in the same way with a gradual reduction in vision especially when reading poor contrast [black on grey] newspapers. People begin to prefer magazine print which has greater contrast," explains David Keegan, ophthalmic surgeon at the Mater hospital in Dublin.
"I advise anyone who experiences this gradual deterioration to see their eye doctor. If there is rapid deterioration with distortion – straight lines looking wavy – I advise people to go to the eye casualty unit in a hospital or their GP."
Injections
The treatment of choice for wet or neo-vascular AMD is anti-vascular endothelial growth factor (known as anti-VEGF) injections into the back of the eye.
“These injections are the best we have to help maintain vision by preventing the damage caused by the leakage in the blood vessels of the back of the eye,” says Keegan.
Those suffering with the wet form of AMD can require monthly injections for a number of years to help maintain their sight.
“I have one patient who I have given 84 injections to both eyes and he is still reading and driving. Before these injections were available, he would have lost 95 per cent of his sight.
“Basically, these anti-VEGF injections are keeping people functioning, independent and out of nursing homes,” says Keegan.
The key to all of this is early diagnosis, which is the purpose of the now annual AMD Awareness Week. During this week – which has just passed – eye tests are available free in opticians and ophthalmic clinics around the States.
Those over 50 are encouraged to have eye checks every two years.
Des Kenny, chief executive of the National Council for the Blind in Ireland (NCBI), says that nowadays people appreciate that sight loss is not necessarily a part of ageing that they have to put up with.
"To unnecessarily lose your sight because of failing to visit an optician is one of the saddest mistakes a person can make and this is all the worse when eyesight can be saved through prompt diagnosis and treatment," says Kenny.
Risk factors
Being overweight, having high blood pressure, smoking and a family history of AMD are risk factors for the condition.
Patricia Quinlan, eye doctor and member of the Irish College of Ophthalmologists, stresses that 75 per cent of blindness is preventable through early diagnosis and treatment.
“In the case of AMD, prevention is aided by maintaining a healthy lifestyle with a balanced diet, blood pressure control, quitting smoking and having regular eye tests.”
Prof Stephen Beatty from the Whitfield Clinic in Waterford adds that research has also shown that vitamin supplements (including lutein and zeaxanthin) can play a role in the prevention of AMD.
“The National Eye Institute in the United States has found that you can reduce the risk of getting AMD by taking appropriate vitamin supplements,” says Beatty, who takes these supplements himself.
