Abstract
Purpose :
The involvement of local and systemic oxidative stresses in intraocular pressure (IOP) elevation and optic nerve damage has been hypothesized in the pathogenesis of glaucoma. To test this, we measured the systemic levels of prooxidants and antioxidants, and the activities of antioxidant enzymes in the aqueous humor.
Methods :
Blood and aqueous humor samples were obtained from Japanese subjects with primary open-angle glaucoma (PG) (n=20), exfoliation glaucoma (EXG) (n=20) and nonglaucomatous controls (n=20). Serum 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. The activities of cytosolic (SOD1) and mitochondrial (SOD2) forms of superoxide dismutase isoform in aqueous humor were measured using enzyme-linked immunosorbent assay technique.
Results :
Compared to control subjects, the BAP values were significantly lower (P<0.05) in PG and EXG subjects. Compared to control eyes, SOD1 and SOD2 concentration were significantly higher (P<0.05) in PG and EXG eyes. The BAP values were negatively correlated with SOD1 and SOD2 concentrations, IOP and the number of antiglaucoma medications.
Conclusions :
Lower systemic antioxidant capacity accompanies up-regulation of higher local antioxidant enzymes, suggesting an increased oxidative stress in eyes with open-angle glaucoma. Determination of systemic BAP values may help in predicting the redox status in aqueous humor and IOP.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.