Vitreous albumin redox state in open-angle glaucoma patients and controls: a pilot study

Abstract

Purpose Numerous studies suggest that reactive oxygen species play a crucial role in the development of glaucoma. Since glaucoma patients exhibit posterior vitreous detachment earlier than controls, it has been suggested that reactive oxygen species-increased in glaucoma-also affect the vitreous. In the present study we evaluated the influence of open-angle glaucoma oxidative stress on the redox state of vitreous albumin. Methods Albumin redox states of the vitreous and plasma were evaluated in 22 subjects-11 open-angle glaucoma patients and 11 controls-matched for age, gender, and vitreous state. According to the redox state of cysteine-34, albumin can be separated into: human mercaptalbumin (the thiol form), human nonmercap-talbumin1 (a reversible modification due to mild oxidation), and human nonmercaptalbumin2 (an irreversible modification due to severe oxidation). Results Albumin of both, the open-angle glaucoma group and the control group, was more oxidized in the vitreous compared to plasma. Furthermore, significantly higher human nonmercaptalbumin1 fractions were found in the vitreous of open-angle glaucoma patients compared to controls. No significant differences were found in the plasma albumin fractions between the groups. Conclusion Our results support the hypothesis that oxidative stress plays a crucial role in open-angle glaucoma and that reactive oxygen species in glaucomatous eyes may also affect the vitreous.

Clinical Significance of Albumin- and Bilirubin-Based Biomarkers in Glaucoma: A Retrospective Case-Control Study

“…In addition, oxidized ALB has been suggested as an oxidative stress marker in such diseases as Alzheimer and Parkinson's disease [26,27]. Efforts have been made to investigate the redox state ALB in patients with glaucoma [28][29][30][31]. For example, the redox state of vitreous ALB has been suggested as a biomarker for the redox situation in the vitreous of patients with POAG [30].…”

“…Efforts have been made to investigate the redox state ALB in patients with glaucoma [28][29][30][31]. For example, the redox state of vitreous ALB has been suggested as a biomarker for the redox situation in the vitreous of patients with POAG [30]. Ischemia-modified albumin levels are significantly higher in patients with PACG, indicating a role as a biomarker available for assessing oxidative stress in the disease [28].…”

Retinal Degeneration and Alzheimer’s Disease: An Evolving Link

“…As in AD, inflammation accompanies glaucomatous degeneration and AMD, and the release of various cytokines from activated microglia is likely to upregulate hepcidin, leading to an accumulation of iron. Oxidative stress is prominent in glaucoma [ 115 , 116 , 117 ], and is exacerbated by the release of TGFβ1 and IL-6, cytokines known to trigger the upregulation of hepcidin. In a recent report, the upregulation of hepcidin in TM cells by TGFβ2 initiated a positive feed-forward loop between TGFβ2, hepcidin, and iron fueled by ROS.…”

Immunological and molecular basics of the primary open angle glaucoma pathomechanism

“…Oxidative stress markers have been found not only in the retina but also in the vitreous body of glaucoma patients [42]. Natural antioxidants, such as curcumin, counteract ROS production.…”