Red blood cell antioxidant enzymes in age-related macular degeneration.

AIMS/BACKGROUND Oxidative damage has been proposed to be involved in the pathogenesis of age-related macular degeneration (ARMD). The purpose of this study was to evaluate whether red blood cell antioxidant enzyme activity correlates with severity of aging maculopathy in affected individuals. METHODS Blood samples were obtained from 54 patients with varying severity of aging maculopathy and 12 similarly aged individuals with normal ophthalmoscopic examination. Macular findings were graded according to a modification of the method described for the Age-Related Eye Disease Study. (AREDS). The activities of superoxide dismutase, catalase, glucose-6-phosphate dehydrogenase, glutathione peroxidase, and glutathione reductase were measured in red blood cells. Haemoglobin content of whole blood was measured, and enzyme activity was determined per mg haemoglobin. RESULTS Multiple regression analysis and ordinal logistic regression analysis were performed to determine whether antioxidant enzyme activity was associated with severity of ARMD. No significant association between disease severity of ARMD and antioxidant enzyme activity was identified for any of the enzymes. CONCLUSION These results do not provide evidence for a relation between oxidative stress, as measured by antioxidant enzyme activity in red blood cells, and disease severity in ARMD.