Background Glaucoma is a highly prevalent eye disease related to optic nerve lesions and visual field defects. Primary Open-Angle Glaucoma (POAG) is a type of glaucoma that occurs frequently with unknown etiology. In this study, we investigated the serum levels of selenium, selenoprotein P1, glutathione, hemolysate glutathione peroxidase1 (GPx1) activity and aqueous humour selenium in POAG patients.
Methods Ninety sex- and age-matched subjects (POAG patients; n=45 and, controls; n=45) with the controlled confounders (smoking, hypertension and alcohol beverages) were recruited on clinical histories and exams. The serum and aqueous humour selenium levels were measured using GFAAS technique. The serum selenoprotein P1 level was assayed with the ELISA method. The hemolysate GPx1 activity and serum reduced glutathione level were also measured using known colorimetric techniques.
Results The serum selenium (P=0.01) and selenoprotein P1 (P<0.001) levels were significantly high in POAG patients. Furthermore, the aqueous humour selenium level was significantly high among patients as compared to controls (64.68±13.07 vs. 58.36±13.76 ng/mL, P=0.02). The results did not show a significant difference (P=0.36) in the hemolysate GPx1 activity between the groups. The cutoff points for intraocular pressure (IOP) and serum selenoprotein P1 parameters were estimated to be 39 mmHg (sensitivity 97.5%; 1-specificity 6.5%) and 188 mg/mL (sensitivity 93.5%; 1-specificity 14%), respectively.