Differences in serum oxidative status between glaucomatous and nonglaucomatous cataract patients

Abstract

Background: Oxidative stress contributes to both intraocular pressure regulation and glaucomatous neuropathy. The systemic redox status (solitary determination) was examined in primary open-angle glaucoma (POAG) patients with cataract and nonglaucomatous cataract patients. Cataract-matched group comparisons appear more precise in the context of oxidative stress evaluation. The aim of this study was to establish if systemic oxidative status in POAG patients was elevated compared with the cataract only subjects.

Methods: The study included patients with primary open angle glaucoma (POAG group, n = 30) and controls (non POAG group, n = 25). Serum concentration of lipofuscine (LPS), malondialdehyde (MDA) and activity of total superoxide dismutase (SOD), and its mitochondrial (Mn-SOD) and cystolic (Cu,Zn-SOD) isoform were measured. Total oxidant state (TOS) and total antioxidant capacity (TAC) in blood were also evaluated.

Results: Significant increase of LPS (p = 0.0002) and MDA (p = 0.005) concentration was observed in glaucomatous patients as compared with controls. Total SOD activity was significantly lowered in the glaucoma group (p = 0.003); serum level of Mn-SOD was significantly lower in glaucoma patients (p = 0.048) however, Cu,Zn-SOD was not. Glaucoma patients presented elevated mean TOS (p = 0.016). Both groups presented with comparable TAC.

Conclusion: Systemic redox balance of cataract patients was significantly altered in the course of glaucoma.

Keywords: Glaucoma; Neurodegenerative disease; Oxidative stress; Serum.

Fig. 1

Pattern ERG representative for subjects from control and POAG group. Lowered N95 amplitude in eye with glaucomatous neuropathy as compared with control. μV/div – microvolts per division; ms/div – milliseconds per division