Age Related Macular Degeneration

The exact cause of Age Related Macular Degeneration (MD, AMD or ARMD) is not fully understood, though recent years have seen a very dramatic advance in understanding of many of the genetic and cellular events that lead to the disease. It is by definition a disease that occurs in older people and does not occur under the age of 50. There are some rare conditions that appear similar to ARMD that affect younger patients (such as myopic degeneration) and they too have benefited from the advances in treatment.

ARMD is the leading cause of blindness in Australia. Approximately 1 Australian in 7 over the age of 50 will have some signs of ARMD. This increases dramatically with age. 14% of Australians over the age of 80 years old will suffer significant visual loss from the condition.

Fine vision, which we need to read, watch television, drive and recognise faces, comes from a small part of the back of the eye (the Retina) called the Macula. It is a very sensitive patch of special nerves that translate the light that is focused onto the back of the eye into vision, and it constitutes less than 5% of all the light sensitive retina. Any disturbance of the function of this small and special part of the eye affects vision. This central part of the eye works hard throughout your life. There is continuous re-cycling of important visual proteins in what is known as the “visual cycle”. For some reason in ARMD this process of recycling becomes imperfect with age. Normally the first signs of the condition is a build up of deposits in discreet clumps at the back of the eye. Ophthalmic surgeons call these “Drusen”. In themselves they often cause no problems. However they can indicate that problems may lie ahead and regular review by an Ophthalmologist is recommended. Dr Hay-Smith has sophisticated equipment that allows him to help design a review programme, if appropriate, for you.

Eventually the disease causes the loss of the important cells that translate light into an electrical signal, which the brain turns into vision. Once this happens you will start to lose vision permanently. When these cells, called photoreceptors, are lost they will never recover. The new treatments for some types of ARMD need to be started early if vision is to be preserved.

How is Age Related Macular Degeneration treated?

The recent development of new treatments for wet ARMD have transformed the outcomes for patients.  A class of drugs call Anti Vascular Endothelial Growth Factor (Anti VEG-F) agents have been approved for the treatment of wet ARMD.  Large trials have shown these drugs to be much more effective than any other treatments (The ANCHOR trials, PRONTO trials and VIEW trials).  The new agents will halt the loss of vision in most patients and in up to 1/3 of patients actually improve vision.  These drugs need to be delivered right onto the retina by a small injection with a tiny needle.  Fortunately this is painless.  The treatment is normally started with 3 injections one month apart.  From then, the condition is treated by extending the inter-treatement intervals, with further injections until the condition settles. Sometimes treatment can be lifelong.  Dr Hay-Smith’s practice is influenced by large international trials that have shown that regular review with treatment as needed has very similar outcomes to monthly treatment – with the great advantage of avoiding unnecessary injections and unnecessary risks. This is widely know as a “Treat and Extend” protocol.

There is no treatment for dry ARMD, but the rate of progression is normally slow.  That said new treatments appear to be not too far away – for example with trials of stem cells now underway in humans.