Macular degeneration
Age-related macular degeneration (AMD), commonly known as macular degeneration, is a disease of the elderly in which degenerative processes take place in the most sensitive part of the retina (film of the eye) which enables one to see fine details.
AMD is one of the leading causes of blindness in the Western world. In Australia, the commonest cause of blindness (presenting visual acuity of less than 6/60) is AMD (48 per cent), and the predicted numbers of Australians who will have low vision or blindness will almost double over the years 2000 to 2024. This estimation was mirrored in an American study, with the prevalence of age-related macular degeneration expected to double in the coming decades because of the projected increase in the ageing population. Apart from its devastating consequences on the patient’s daily life, it has significant economical impact on society. There is clearly an urgent and important need for further research on the management of macular degeneration.
AMD can be broadly classified into dry and wet types. Wet AMD implies that there is a leakage of fluid or blood in the central part of the retina. The initial symptoms are frequently distortion or loss of central vision — suddenly in wet AMD or gradually in dry AMD. People with any of these symptoms should seek a referral from either their GP or optometrist to an ophthalmologist with a special interest in the retina as soon as possible.
The aetiology of AMD is multi-factorial including physiological ageing, genetic, dietary, and environmental factors. Various therapies are used including dietary/vitamin supplements, laser treatment with or without photosensitising dye, radiotherapy, surgical removal of scar tissue, and recently, pharmacological treatment (e.g. anti-VEGF (vascular endothelial growth factor) therapy — Avastin (bevacizumab), Macugen (pegaptanib) and Lucentis (ranibizumab)).
Ninety per cent of severe visual loss from AMD is due to the complication of the wet type of macular degeneration. The latest treatment which has revolutionised the management of wet AMD is the injection of a special drug called Lucentis into the middle of the eye (vitreous). Unlike previous treatments, e.g. laser therapy, which tended to slow down/limit the loss of vision, a number of patients who received the Lucentis injection actually noticed an improvement in vision. The original trial of Lucentis suggested injections every month for 2 years. The latest figures suggested that one would expect to receive at least 5–6 injections in order to control wet AMD. Previously costing A$2000 for the drug alone per injection, from 1st August, 2007, Lucentis will be listed on the PBS (Pharmaceutical Benefits Scheme) in Australia.
Much research is being undertaken in this field and it is likely that, over the next decade, there should be more major advances.
Last Reviewed: 22 June 2007
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