Glaucoma and Antioxidant Status

Glaucoma, one of the leading causes of irreversible blindness in the world, is defined as a slowly progressive optic neuropathy characterized by retinal nerve fiber and visual field loss. Although increased intraocular pressure is the major risk factor for glaucoma, other risk factors include advanced age, genetic predisposition, family history, gender, ethnic background, myopia, and diabetes. Recent evidence indicates that oxidative stress by reactive oxygen species, occurring not only in trabecular meshwork but also in retinal ganglion cells, plays an important role in the pathogenesis of open-angle glaucoma. The aim of this chapter is to assess, based on the current literature, the role of oxidative stress in the pathogenesis of glaucoma and antioxidant status in glaucoma. © 2014 Elsevier Inc. All rights reserved

Protein carbonyl levels in the aqueous humour and serum of patients with pseudoexfoliation syndrome

Purpose: Protein oxidation is an oxidative stress marker and the oxidation of proteins is analysed by measuring the carbonyl groups. Protein oxidation can have a role in the physiopathology of pseudoexfoliation (PEX) syndrome. The aim of this study was to investigate the protein oxidation in the aqueous humour and serum of cataract patients with and without PEX. Methods: A multicenter study was carried out. Aqueous humour and serum samples were collected from patients who underwent routine cataract surgery. Patients were divided into PEX (n = 29) and control (n = 27) groups. Patients had no elevated intraocular pressure or glaucoma. Spectrophotometer was used to measure protein carbonyl (PC) levels in the samples. Results: Mean PC concentration in the PEX aqueous (2.18 ± 1.51 nmol/l) and serum (119.62 ± 13.2 nmol/l) samples was significantly higher than that measured in the control aqueous (1.31 ± 0.47 nmol/l) and serum (105.85 ± 11.76 nmol/l) samples, respectively (P < 0.001). Conclusion: The increased PC levels in the aqueous humour and serum of PEX patients suggest that protein oxidation may play a role in the physiopathology of PEX

Use of melatonin to prevent selenite-induced cataract formation in rat eyes

Purpose: To evaluate effects of melatonin on sodium selenite-induced cataract formation. Methods: Twenty-three Sprague-Dawley rat pups were randomized into three groups. Group 1(n = 9), injected with selenite (s.c.) on postpartum day 10; group 2 (n = 7), injected with selenite (s.c.) on day 10 plus melatonin (i.p.) on days 8-15; group 3 (n = 7), saline-injected controls. Development of cataract was assessed weekly under a dissection microscope. Rat lenses and serums were analyzed for antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT); oxidative stress indicators xanthine oxidase (XO) and malondialdehyde (MDA), a marker of lipid peroxidation; and protein carbonyl (PC), a marker of protein oxidation. Results: Significant differences (p < 0.05) were seen in cataract development by the three groups. All rats developed dense nuclear cataract in group 1. Dense nuclear cataract was not observed in group 2: five of seven rats developed minor cataracts, while the other two had clear lenses. In control rats (group 3), all lenses remained clear. In selenite group (group 1), lens and serum levels of MDA, PC, and XO were significantly higher and levels of SOD and CAT were significantly lower than those in control group (p < 0.001). In selenite+melatonin group (group 2), lens and serum levels of MDA, PC, and XO significantly decreased and levels of SOD and CAT significantly increased when compared with selenite group. Conclusions: Studies with the rat selenite cataract model strongly support the activity of melatonin as an endogenous antioxidant and anticataract agent. Copyright © Informa Healthcare