Use of metabolomics in age-related macular degeneration

Age-related macular degeneration (AMD) is a major cause of irreversible central sight loss in the elderly. Many factors affect disease onset and progression, and these include age, environmental stressors such as smoking, diet, inflammation and genetic polymorphisms, all of which are likely to influence metabolism. In some complex diseases, metabolomics, which involves the identification of a metabolic fingerprint in a biofluid or tissue, has been shown to discriminate metabolic changes associated with different disease processes and to identify specific phenotypes. We have applied metabolomics, in the first study of its kind, to analyse, using NMR spectroscopy, both serum and urine metabolic characteristics in patients with dry and wet AMD (n=104). NMR spectral analysis showed good clustering as well as separation among the serum and urine from dry and wet AMD patients. The results show that metabolite profiles can distinguish dry and wet AMD, but that the pathways involved, glycolysis, urea cycle and Kreb’s cycle, are involved in both forms of the disease. It is likely that the pathogenesis of dry and wet AMD is similar and that the severity of ocular damage and systemic inflammation would account for the distinguishing profiles. These data support the use of metabolomics in identifying biological pathways involved in pathogenesis of AMD, but not in the diagnosis or prognosis of disease