- © 2004 Canadian Medical Association or its licensors
Thank you for Erica Weir's Public Health article on age-related macular degeneration (ARMD).1 The term for this condition sounds like an apology for our inability to identify a better cause, but in fact genetics plays a large role in a person's predisposition to macular degeneration. Several genes may be associated with macular degeneration, including ABCA4, VMD2, EFEMP1, TIMP3,2 ELOVL43 and CRX.4 However, a search for mutations in these genes in patients with a diagnosis of ARMD has been disappointing, except in the case of ABCA4. Patients who carry mutations in both ABCA4 alleles have an autosomal recessive disorder called Stargardt disease.5 Allikmets6 has shown a significantly higher incidence of mutations in the ABCA4 gene among patients with ARMD than in a control population. These mutations may contribute to the higher risk of vision loss from ARMD among first-degree relatives of patients with the condition, estimated at 4 times the risk for the general population.7
How can ARMD be prevented? As mentioned by Weir, stopping smoking and eating a healthy diet are both important. In particular, eating fish at least twice a week reduces the risk.8 Fish is an excellent source of omega-3 fatty acids, in particular docosahexaenoic acid, the predominant highly unsaturated fatty acid of the retina. With people now living into their 80s, a healthy lifestyle and a healthy diet are important not only for general well- being but also for good vision.
Ian M. MacDonald Matthew A. Lines Ocular Genetics Laboratory University of Alberta Edmonton, Alta.
References
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