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A study is conducted to identify and understand modifiable risk factors in age-related macular degeneration, which is a leading cause of irreversible blindness in Australia and other Western countries. Very little information on modifiable risk factors is consistent and well validated except that of smoking and hence a low-fat diet rich in vegetables containing lutein, zeaxanthin and antioxidants seems a reasonable recommendation along with further research to pinpoint the culprits.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ajo.2007.12.005 Byline: Elaine W.-T. Chong (a), Andreas J. Kreis (a), Tien Y. Wong (a)(b), Julie A. Simpson (c)(d), Robyn H. Guymer (a) Abstract: To review systematically the evidence currently available on alcohol consumption and the risk of age-related macular degeneration (AMD). Author Affiliation: (a) Centre for Eye Research Australia, The University of Melbourne, Victoria, Australia (b) Singapore Eye Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore (c) Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, The University of Melbourne, Victoria, Australia (d) Cancer Epidemiology Centre, The Cancer Council of Victoria, Victoria, Australia. Article History: Accepted 5 December 2007

Objectives: To investigate the role of 2 specific alleles of the Stargardt disease gene (ABCA4) in the pathogenesis of age-related macular degeneration (AMD). Secondary objectives were to investigate differences in frequency of the G1961E allele in selected ethnic groups as well as to examine the segregation of both G1961E and D2177N alleles in 5 multiplex families with AMD. Methods: Five hundred forty-four patients with AMD and 689 controls were ascertained from 3 continents. Blood samples from 62 normal individuals of Somalian ancestry were also obtained. Participants were screened for the presence of these ABCA4 alleles with a combination of restriction digestion and single-strand conformation polymorphism analysis of polymerase chain reaction amplification products. Detected alleles were confirmed by DNA sequencing. The number of subjects exhibiting the G1961E or D2177N variants were compared between AMD and control groups using a 2-tailed Fisher exact test. Results: There was no significant difference (P [is greater than] .1) in the frequency of the G1961E and D2177N alleles in patients with AMD (2.2%) vs controls (1.0%). In contrast, there was a significant difference (P [is less than] .001) in the frequency of the G1961E alleles between normal individuals of Somali ancestry (11.3%) and normal individuals from other populations (0.4%). There was no evidence of cosegregation of these alleles and the AMD phenotype in the 5 multiplex families with AMD examined. These two ABCA4 alleles were slightly more frequent in patients with AMD with choroidal neovascularization (2.7%) than those without this complication (2.5%). Conclusions: Somali ancestry is more than 100 times more strongly associated with presence of the G1961E allele than the AMD phenotype. This study did not find any statistically significant evidence for involvement of the G1961E or D2177N alleles of the ABCA4 gene in AMD. Clinical Relevance: The ABCA4 gene is definitively involved in the pathogenesis of Stargardt disease and some cases of photoreceptor degeneration. However, it does not seem to be involved in a statistically significant fraction of AMD cases. Arch Ophthalmol. 2001;119:745-751