Abstract
Purpose: :
Involvement of local and systemic oxidative stresses in intraocular pressure (IOP) elevation and optic nerve damage have been hypothesized in the development and progression of glaucoma. To test this hypothesis, systemic levels of oxidative stresses were measured by blood biochemical analysis in patients with glaucoma.
Methods: :
Peripheral blood samples were collected from Japanese patients with primary open angle glaucoma (PG) (n=206), exfoliation syndrome (EX) (n=199), and cataract (CT) (n=126). Plasma levels of lipid peroxides, ferric reducing activity, and thiol antioxidant activity were measured by diacron reactive oxygen metabolites (dROM), biological antioxidant potential (BAP), and sulfhydryl (SH) tests, respectively, using a free radical analyzer (FREE, Wismerll Company Ltd., Tokyo, Japan). The values were statistically compared among groups by using t-test combined with the Bonferroni correction for multi-group comparisons.
Results: :
In the CT, PG, and EX groups, measured values (mean +/- SD) were 348±56, 355±63, and 357±69, respectively, for dROM (U.CARR); 2033±252, 1951±282, and 1969±252, respectively, for BAP (µmol/L); and 617±99, 614±98, 584±91, respectively, for SH (µmol/L). The differences were statistically significant between CT and PG groups for BAP (p=0.0062), between CT and EX groups for SH (p=0.0017), and between PG and EX groups for SH (p=0.0026). After the adjustment for differences in age and sex among groups by using multiple regression analysis, lower BAP values correlated significantly with the PG (p=0.0155) and EX (p=0.0049) groups. By linear regression analysis, lower SH values correlated significantly with older age (r=-0.37, p<0.0001). None of the values were significantly different between higher (≥ 21 mmHg) and lower (< 21 mmHg) baseline IOPs in the PG group, or between with and without glaucoma in the EX group.
Conclusions: :
Lower systemic ferric reducing activity may be involved in the pathogenesis of PG and EX. The age-related decline of thiol antioxidant activity may be an epigenetic risk factor for the development of EX.
Keywords: oxidation/oxidative or free radical damage • antioxidants • clinical (human) or epidemiologic studies: risk factor assessment