Metabolomics in non-arteritic anterior ischemic optic neuropathy patients by liquid chromatography-quadrupole time-of-flight mass spectrometry

Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) is a rare ischemic disease that affects the optic nerve. Pathophysiology and mechanism of ischemia of NAION remain uncertain, so the aim of this work is to establish the first metabolic fingerprinting of patients with NAION to discover possible new biomarkers. Twenty-four patients, aged 39-85 years, diagnosed with NAION, after a sudden loss of vision, were recruited for the study. Plasma samples of patients and controls were fingerprinted with liquid chromatography coupled to quadrupole time-of-flight by electrospray ionization, and obtained data were filtered, aligned and statistically analysed to identify new biomarkers. The identity of compounds that were found to be significant in class separation was later confirmed by obtaining the characteristic MS/MS spectra and online databases. In general, biochemical and metabolic profiles between patients and controls did not show profound differences, but NAION patients presented disturbances in the phospholipid composition which lead to reduced plasma values of LysoPCs. Altered levels of other metabolites, such as l-Palmitoylcarnitine, have been detected and could be considered as potential biomarkers.