The central vision is decreased due to age related changes at the central retina (macula).
Deposits in the layer under the retina can build up with time and can lead to thinning of the central retina (‘dry’ macular degeneration). A second complication of age related macular degeneration involves the growth of abnormal blood vessels from under the retina into the retina. This can lead to fluid or blood under the retina (‘wet’ macular degeneration).
Modern treatment with intra-vitreal injections of anti-VEGF medicines such as Lucentis have revolutionised the prognosis for wet ARMD. Previously, without injection treatment, the prognoisis was usually legal blindness (total loss of central vision). Now, with appropriate antiVEGF treatment, sometime requiring supplemental treatment with PDT (“cool”) Laser treatment or other intravitreal medicines, the prognosis is often quite favourable. However, the prognosis does depend on how early the patient presents with their wet ARMD – late presentation leads to late treatment and poor results. Once medically stabilised, other non-medical help with optimum lighting, glasses and sometimes magnifying devices are helpful in this condition.
The long-term outlook for peripheral vision is good. In wet macular degeneration the long term outlook for central vision is usually poor, unless antiVEGF treatment is given early and repeatedly. This condition never causes complete blindness, although it may decrease central (reading) vision. The peripheral (side) vision is retained. Thus a patient with severe macular degeneration will still be able to get around independently.
Often the condition presents in one eye and the other eye retains normal vision. However, it can affect the other eye in approximately 20% of cases and it is therefore useful to monitor the other eye by looking at a piece of graph paper (Amsler Grid) to check for increasing distortion or blackouts of vision in the central visual field. The patient with macular degeneration should monitor their vision every week or so, and present for an eye examination within a week if there are dramatic changes in central vision.
Some people take anti-oxidant vitamins for macular degeneration. A study conducted in late 2001 suggested a benefit if anti-oxidant vitamins were taken in addition to a good diet. The study found that patients with wet macular degeneration in one eye had a 28% risk of wet macular degeneration occurring in their fellow eye. With vitamins and good diet this risk was decreased to 20%. In patients who only have mild macular degeneration in both eyes, the probability of progression to advanced age related macular degeneration is only 1.3% even without taking antioxidant vitamins.
It is therefore recommended that patients who have bad vision in one eye from age related macular degeneration should consider taking a combination of Vitamin C, Vitamin E, β-carotene and Zinc to try to prevent bad vision occurring in the fellow eye (eg. Two Macuvision tablets per day with two Nature’s Own Beta Carotene 6mg tablets per day).
Warning- Patients who smoke should not take β-carotene due to the increased risk of cancer in smokers who take supplemental β-carotene
Dr Bourke explains what macular degeneration is, and answers the question: is it curable?
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