Levels of aqueous humor trace elements in patients with open-angle glaucoma

Purpose: Trace elements might play a role in the complex multifactorial pathogenesis of open-angle glaucoma. The aim of this study was to analyze concentrations of trace elements in aqueous humor samples of patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PEXG). Patients and methods: Thirty-three aqueous humor samples were obtained from patients undergoing cataract surgery: 12 patients with POAG (age 65.3 +/- 10.50, female 8, male 4), 10 patients with PEXG (age 65.9 +/- 11.27, female 6, male 4) and 11 patients without glaucoma (age 69.5 +/- 13.70, female 7, male 4) serving as controls. Aqueous humor levels of cadmium, iron, manganese, cobalt, copper and zinc were measured by Flow-Injection-Inductively-Coupled-Plasma-Mass-Spectrometry (FI-ICP-MS). Results: From the statistical evaluation, we observed that patients with POAG had significantly higher aqueous humor levels of zinc (p = 0.006) compared to controls. Increased aqueous humor levels of zinc were also observed in patients with PEXG in relation to control (p = 0.0006). For iron we observed a significantly reduction in PEXG compared to control (p = 0.002) and a significant difference between POAG and PEXG (p = 0.0091). No significant differences were observed in aqueous humor levels of manganese, cobalt, copper, cadmium between glaucoma and control patients. No differences were seen for iron (POAG vs. controls). Analysis of trace element ratios was added. Conclusion: Significant differences in aqueous humor levels of zinc and iron between glaucoma and control patients support the hypothesis that these trace elements are involved in the pathogenesis of open-angle glaucoma.