Plasma Ascorbic Acid and Non-Enzymatic Antioxidants Level in Unoperated Cataract Patients

Abstract

Free radicals have been implicated in the pathology of several diseases including cataract. Ascorbic acid functions as the major chain breaking antioxidant vitamin in the aqueous phase. Bilirubin, albumin and uric acid are regarded as natural antioxidants. There are conflicting reports on plasma concentrations of these antioxidants in cataract patients. 89 subjects consisting of 55 cataract patients and 34 control subjects were recruited for the study. The mean age of the subjects was 61± 11yrs. Mean plasma ascorbic acid level was significantly lower in cataract patients (0.33± 0.27) when compared with age matched control group (0.59 ±0.37) (p< 0.05). A significant increase in mean plasma bilirubin was observed in cataract patients when compared to the corresponding controls. Plasma uric acid levels showed a positive correlation with ascorbic acid (r =0.40, p <0.05). A positive correlation between plasma albumin and bilirubin levels in cataract patients (r=0.33, p <0.05) was also observed. A positive correlation between plasma ascorbic acid and uric acid levels is in agreement with the established antioxidant interaction theory. The disease process of the cataract and the resulting oxidative stress due to the chronic nature of the disease may result in an increased consumption and subsequent demand of ascorbic acid by the body to efficiently combating the excess free radical load generated in cataract patients. These results therefore suggest that there may be a need for increased ascorbic acid intake in cataract patients especially before surgery or other forms of therapy..

Keywords: Antioxidant, Ascorbic acid, Cataracts, Free radicals, oxidative stress

Nigerian Journal of Health and Biomedical Science Vol. 6 (1) 2007: pp. 38-41