Determination of copper by AAS in tear fluid of patients with keratoconus

• Published in: Analytical biochemistry Vol. 623; p. 114174
• Main Authors: Corbini, Gianfranco, Dreassi, Elena, Chiasserini, Luisa, Girolamo, Matteo Maria, Mellace, Pierfrancesco
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.06.2021
• Subjects: AAS; absorption; Biomarker; biomarkers; copper; Copper determination; corneal diseases; Keratoconus; Schirmer test stripe; Tear fluid; Tear fluid; Copper determination; Biomarker; AAS; Schirmer test stripe; Keratoconus
• ISSN: 0003-2697; 1096-0309; 1096-0309
• DOI: 10.1016/j.ab.2021.114174

Keratoconus (KC) is the most common degenerative corneal disease and no single biomarker for KC has been discovered. Its causes have not yet been clarified and this work aims to be a contribution to the deepening of the knowledge of this disease and a preliminary data to the evaluation of the possibility of the use of copper (Cu) concentration in the tear fluid as a specific marker. A tear fluid sampling and Cu determination by spectrometric atomic absorption method was optimized to determine Cu levels in the tear fluid of patients with KC compared to that of healthy patients. Results demonstrate that in the KC subjects (n = 6) the concentration of Cu ions was 325.5 ± 110.7 ng/ml, while in the control group was 141.3 ± 71.1 ng/ml. A significant increase in Cu ion levels in the tear fluid was observed in the KC group compared to the control group (p value < 0.001). •Atomic Absorption Spectroscopy is able to determine Cu levels in tear fluid.•The Schirmer strips are a reliable method to sampling tears for Cu quantification.•In tear fluid of patients with keratoconus there are a significant increase in Cu.•Cu concentration in the tear fluid could be used as a marker for keratoconus.